Transmission



June 13, 1944. J cRAlG 2,350,989

- TRANSMISSION Filed May 29, 1940 2 Sheets-Sheet l rr 7 I l AW@ c414 W, W

June 13, 1944. J CRAIG A 2,350,989

' TRANSMISSION FiledMay 29, 1940 2 Sheets-Sheet 2 Patented June 1 3, 1944 uurrao srsrss 2,350,989 TRANSMSSION Burnie J. Craig, Los Angeles County, Calif. Application May 29, 1940, Serial No. 337,890

2 Claims.

This invention relates particularly to fluidturbo devices wherein a circuit for the working medium is defined by a primary driving memher. and a secondary driven member each of which may include a grooved and/ or vaned member forming at least a portion of the boundary of the circuit. It will be understood, however, that the invention, in whole or in part may also be employed in connection with hydraulic converters or in other devices wherein liquid-like means serves to transmit motion and-or cushion movement, etc. between two relatively movable members. The present invention is described herein as embodied in'a fluid coupling which is operated with the medium remaining at all times in the. circuit although the invention may be used with constructions wherein the medium is pumped or otherwise placed into or out of driving position e. g. where it is run intoa reservoir.

The invention as herein described is especially adapted for use in motor vehicles and similar constructions wherein the power of a prime mover is transmitted through a fluid coupling to vehicle propelling means.

Prime movers of the type mentioned are usually multiple cylinder engines in which the pistons are reciprocated by ignition of fuel and the vehicle has been propelled through the action of transmission gearing which provides, due to engine impulses, a periodically variable torque, so that the smooth forward motion present when a vehicle is propelled by steam or electric motive power is not secured and many efforts have been made to smooth out the impulse-by-impulse motion as, for example, by providing for a limited resiliently cushioned movement of the engine, etc. Some recent automotive vehicles have included a fluid-turbo device in the nature of a fluid coupling in which a liquid such as oil working in a toroidal path passes from one vaned element to another to eifect a coupling action. The liquid in normal low slip driving moves in a path about the axis of the elements. The liquid also moves in its circuit in planes intersecting the element axis.

The liquid entering the vanes of the primary at their inner periphery iollows the contoured path to the outer edge whence it passes to the secondary and in thus moving outwardly the velocity is increased and, although the cross sectional area of the circulating liquid column may not vary, the cross sectional shape of the liquid column 15 rapidly changed and as the liquid moves inwardly in the secondary the velocity is reduced and the cross sectional shape is again changed. The

shape of the liquid column is thus in a continual state of change being subject to what might be termed a kind of kneading action, or motion, in addition to the movements mentioned in the preceding paragraph.

Further, the outer periphery of the path'of the liquid being defined by the walls of the elements, particles of liquid next to the confining walls do not change their distance from the wall but do change their angular speed in the planes intersecting the element axis. The particles of liquid most remote from the confining wall alternately increase and decrease their angular speed in the circuit. The particles of liquid intermediate the inner and outer periphery of'the toroidal circuit also partake of the same changes of angular speed according to their position.

It thus appears that the particles of liquid in the circuit (except possibly those in the outer periphery) have continuous change in velocity while the kneading action and the rotation and the planar circuit movement mentioned in the preceding paragraphs is taking place.

In order that fluid turbo devices may transmit power emciently the circuit defining walls are so shaped that the movement of the medium is normally not subject to abrupt path changes.

With such careful design, however, in operation when the relative speed of the elements is rapidly varied as when starting a vehicle on a hill when the engine speed is relatively low and the slip high, the torque transmitted may suddenly rise and surges occur. The surges apparently resuit from circulation irregularities or circulation break-down and re-establishment which breakdown and re-e'stablishment may occur quickly and sometimes frequently, resulting in an unsatisfactory driving efiect. The surges tend to overload the engine if the inertia of the driven equipment is high. The added force resulting from the surges is thrown into the working parts so I crosses over from one element to the other is not serious since the vanes are uslmlly made of thin\ driving has resulted.

the engine and the tending to cushion upon variation in the no and a cushioned drive results. invention is to provide 'wantionwillbe apparen turbance since the liquidon striking the edges of the vane members is sublect to a slight eddy or similar action and efflciency loss probably results even under ideal conditions withthe old practice. The unsatisfactory results mentioned have been due, in part at least, to the fact that the coupling liquid when functioning in undisturbed circuit flow provides a relatively rigid and noncompressible fluid column. As a result practically all or the motor impulses have been transmitted to the drivenfl member. tions which tend to disturb the uniform liquid flow, such as changes in speed 01 the input shaft, change in torque of load shaft, etc. result in'circuit disturbance. This appears to be due-to the fact that the changes must be'taken care of largely by a change in the flow path, which flow path change may be so extreme asto cause surges or circulation collapse and re-establishment.

'Thus, have not produced under other conditions more or less objectonable However, notwithstanding the objections and "notwithstanding eificiency losses, particularly in converters, couplings and converters are finding wider use from time to under ideal conditions,- fluid-turbo drives time and the general object of the present invention is to provide a construction and a medium. which removes or tends to reduce certain disadvantages in the old practice;

Seeking to overcome the obiection noted the I invention'as disclosed herein contemplates the driving connection between driven wheels of a connection or coupl ng which has energy storing and releas- Another object of the invention is to provide a fluid turbo device which includes a circuit path insertion into .iihe

' with a novel mobile mass therein which has such properties that its action results in a more uniiorm power flow., Another object oi the invention is tosecure the mentioned and/or other advantageous results by providing a fluid turbo mediumwhich an entirely smooth drive and Further conditween two or more has novel energy storing and releasing properties.

Another object of the invention is to provide anovel combination fluid turbo device and driving medium therefor.-

A more specific object of the invention is, to provide a fluid turbo device wherein a novel mobile mass in the circuit has such properties smooth normal driving action to cushion and/or to restore-the smooth flow and also tends to avoid surges and/or circulation collapse. p a

' turther object of the invention is to provide a fluid -turbcd'evice in which the driving medium is elastic and/or resilient and/or compressible and/or has energy storing and releasing ties so' that it tends to maintain the proper driving relation and may at the same time act and react, and be acted upon while moving in its usual path so that eircuitchanges are tov a certain extent damped out by action oi the driving mobile mass and thus a more uniform power flow Another object or the a fiuid turbo device including novel wall portions and/or vane members.

Other objects and the advantages 01 this inrrom the to owing -deengine impulses and whichdriving action'ctends pron rpling but. it

sheet metal, but there is, however, a slight disscription taken in connection with the accompanying drawings, wherein:

Fig. 1 is a fragmentary sectional view through a fluid turbo device;

Fig. 2 is a central sectional view showing one of the fluid mass members;

Fig. 3 isa central sectional view showing another modified member before vulcanization;

Fig. 4 is a viewsimllar to Fig. 3 showing the modified member after vulcanization;

Fig. dis a central sectional view showing a further modified member;

Fig. 6 is a fragmentary sectional view similar to Fig. 1 showing device;

' Fig. 7 is the fluid mass in .the turbo a sectional view, partly in elevation and partly diagrammatic, showing the apparatus for making the members;

Fig. 8 is an enlarged fragmentary sectional view showing the mold member;

Fig. 9 is an enlarged plan development of one of the mold members:

Fig. 10 is a side elevation showing an automotive vehicle with Fig. 11 is a view similar to Fig.1 showin a modification;

Fig. 12 is a fragmentary sectional view taken on line i2-l2, Fig. 11;

Fig. 13 is a central sectional view showing one form oi'the invention embodied in a cushion device; and

Fig. 14 is a view similarto Fig. 11 showing one form oithe invention embodied in a clutch device.

Reierring'to the drawings by reference characters the invention as disclosed is employed in a hydro-dyamic device which is shown as a couwill be understood that this is by way of illustration only and that the invention may be employed with other fluid turbo devices such as converters or with other devices which transmit motion or cushion movement, etc. be-

The device is shown as used wlth'an automotive vehicle if having an engine I! which may be a multi-cylindered gasoline engine which drives a, flanged member I i to which a rotatable and is adapted to be connected to drive wheels II of the vehicle either directly, by gearing, or through a suitable change speed device 22. The illustrated construction of the vehicle is oi. the usual front engine-rear wheel drive type but the invention is applicable to other typeset ene arrangement and drive. The fluid turbo elements it and i1 include vanes 23 and 24, respectively, and their walls are contoured to form fluid receiving What: 2! which are suitably spaced. The vanes 23 and 24 are notched as at I to receive semi-circular guide rings 21 which aresuitably welded. orotherwiscsecured in place.

' In operation power is transmitted irom the driving shaft to the driven-shaft by 8 flowin mass which iormsaworking clrcuitinthe the invention applied there relatively movable membersf seal is maintained "20. The shaftll constitutes a load output shait 25 and which when the primary is is rotated passes between the vanes 23 thereof into the vanes 24' in the secondary to cause the latter to rotate. .Inprior constructions wherein oil or other non-yielding material was employed, the

efiiciency of operation depends upon the speed of rotation of the primary, the position of the primary relative to the secondary, the contoured shape of the pockets, the shape and distribution of the vane members, the relative speed of the primary and the secondary, the load torque relative to the input, etc. and there has been no provision made whereby the driving mobile connection could adapt itself to variations in the forementioned or other, conditions so that a smoother driving action would result.

According to the present invention the fluid turbo device employs a coupling mass which in one disclosed form consists of a plurality of small members indicated at 28- and shown as spherical and having a cavity 29 filled with compressed air. The members 28 may be made of rubber, artificial rubber or other material having the requisite properties, and if desired the members may have particles 30 (Fig. 2) of metal or other material embedded therein to vary their specific gravity. The particles 30- preferably are removed somewhat from the surface 3| of the members 28. The members 28 may be employed alone as a driving medium or they may be employed with a suitable liquid such as oil or other material which does not seriously afiect the material of which the members are made. If a liquid is employed it is preferably used in such quantities as V to at least fill the voids between the members 28 as shown at 32 in Fig. 6.

mobile mass operates under a new normal of contained energy content.

'Regardless of the time required to store or release energy the tendency is to prevent or lessen the effect of abrupt torque increase or load input etc. and the medium is constantly taking the extremes of torque increase or load input and is reducing the efiect of these extremes without loss of operating eficiency and while maintaining a normal balanced state between energy storing conditions and energy releasing conditions.

Thus by virtue of the properties of the mobile mass the periodic torque variations delivered by an internal combustion engine are largely damped out so that'a smoother drive results. Further the turbulence and surging occurring under certain driving conditions with the previous fluid are largely eliminated; n

In order to produce the members 28 a novel apparatus indicated at 35 in Fig. 7 may be employed. As shown the apparatus includes upper and-lower drums at and 31 which are suitably Each drum is hollow and shaft 38 which communiof the drum and with the supported for rotation.

atmosphere.

As shown in Figs. 8 and 9 each of thedrums is I provided on its exposed surface with a plurality The amount of liquid and the size and weight of the members 28 may be varied to suit the particular requirements of the structure with which they are employed by controlling the size of the cavity 29, the wall thickness, and the use or absence of particles 30. The specific gravity of the members 28 may be made the same or greater or less than that of the liquid 32,

The properties of the medium'are such that it responds quickly to changing conditions. Under normal driving the medium might be said to be tensed, at any one time, to correspond to the con dition applied at that time andto be ready to respond to a further change should such occur."

For instance, if the applied torque suddenly increases, the medium will immediately store added energy so that less circulation disturbance will result. The stored energy will be later released in accordance with the driving conditions. This result is true, to a degree, regardlessofwhether the changes mentioned are large as duringrapld acceleration'with high slip or whether they are small as in normal conditions below a normal. The storing and reof substantially hemispherical mold cavities 89 which communicate through holes dll with the interior of the drum. Each mold cavity 39 is surrounded by a more or less sharpened peripheral edge portion M. The portions M on the two drums are in substantial engagement where the drums are.tangent.

The apparatus 35 is preferably arranged in a room 42 where air under pressure is maintained. Access to the room 42 may be through a suitable airlock 43.' The apparatus 35 includes supports 44 for rolls of rubber, plastic material, or other stock 45 and the construction is such that when the drums carried about the drums.

[normal and releases this stored energy under leasing of energy quickly balances whereupon the 7s The drums being hollow and being bled shafts, the interior of the through the hollow drums is under less pressure than .the exterior thereof .so-that-the stock 45 being more or less plastic is forced by the compressed air into the mold cavities 39 and rotates with the drums until the edge portions 4| contact whereupon the two halves are squeezed together as shown in Fig. 8. The drums may be heated so that a slight cure results as the drums rotate. The stock with the minute hollow rubber members preferably united by fins pass from the drums and is carried on supporting devices 46 through a vulcanizer 41. The minute balls are preferably held in sheet form until vulcanization is complete whereupon. they are separated in any desired manner as by multiple punches for instance.

The making of the balls having occurred in a room, filled with compressed air the balls when finished are inflated by the contained ain'the pressure of which has been predetermined.

'In order to prevent excess leakage through the holes 40 which are not sealed by the sheet stock, endless elastic belt members 48 (see Fig. 7) may be employed. These members pass over rollers 49 and are dragged along by the adjacent drums so that the holes 40 beneath the belts 48 are closed thus reducing leakage.

type of member is member may be made by In Figs. 3 and 4 another indicated at 50. This taking a core 51 able member, such as amorphorus graphite com- 36' and 31 are rotated the stock 45 is.

which may consist of some suitapellet. The core'5l with compressed air which sponds in an improved The fluid turbo elements Wand l1 are preferbined with a gas'releasing material such as ammonia powder and a binder such as clay to form is then covered with latex or similar material and vulcanized with the gas liberatedfrom the ammonia powder serving to providepressure for vulcanization and for infiation after the member is vulcanized. The member may be vulcanized in a chamber filled will prevent the gas liberated by the ammonia powder from expanding the latex cover unduly. The graphite and clay in the member 50 serve to add weight to the finished product.

In Fig. -5 the member 52 includes a ball 53 made of metal or other suitable material with a resilient and elastic covering 54 as of rubber vulcanized thereto.

The members 28 and 50 are compressible as well as resilient and elastic due to the contained gas. Rubber being relatively non-compressible the members 52 are resillent and elastic but are relatively non-compressible. When the members 28 and 50 are employed with a liquid or alone they form a liquid-like mass which is compressible, elastic and resilient.

The size of the members used in the fluid mass may be suitably varied to suit the conditions in each installation. The width of the space between the turbo elements may in a measure (16-. termine the size of the members, also the pressure within the contained members, their wall thickness, resiliency, elasticity, etc. will be suitably determined by the requirements.

The specific gravity of the members may be varied as required. For instance the members 28 when used with a liquidmay have substancured that they have resilient properties so that in effect :a resilient lining is provided for the contouredmembers. i

The vanes and 11 may also be made of reslient artificial rubber and if desired may be integral with the lining portion. The vanes may include reinforcing means if desired.

The fluid masses previously described may be employed in the modified structure as the driving medium although the action of the resilient linings 12 and 13 and/or the action of the resilient vanes 14 and 15 causes the oil or other liquid heretofore used to operate in an improved manner.

In Fig. 13 the fluid mass of the present invention is indicated as at 55 as placed in a cylinder 55 such as a shock absorber cylinder in which a piston 51 recprocates. In the disclosure the fluid mass 55 includes a liquid the quantity of which under atmospheric pressure is sufficient to at least fill the voids between the members constituting the mass. The skirt of the piston 51 is shown as relatively long and when prestially the same specific gravity as that of the liquid. The members 50 preferably have a specific gravity less than that of the liquid while the members 52 preferably have a greater specific gravity than that of the liquid.

As an illustration ofmaterial employed the artificial rubber known as Neoprene" may be employed and the liquid might well be S. A. E. No. 30 oil in which Neoprene" swells but slightly and retains its-tensile strength well although the type of material and oil may be varied as conditions require.

The medium is preferably of such a nature that it remains substantially uniform andstable under extremes of working conditions and the members should preferably be so made that they will not be unduly tensed under normal driving conditions so that they may store energy or release energy. l

The members should preferably all be of the same size although in certain installations members of different sizes may be employed tobetter advantage.

The flu d mass instea'dof including individual members may include a mass of latex or similar material cured so that it maintains its mobility and flow characteristics and which has such resilient,. elastic, or other properties that it remanner in the circuit.

as bodies 14 and .15 with the inner portions of the walls .12 and 13 thereof of such material and so sure is applied to the piston the compressible, resilient mass 55 has its volume reduced and some of the liquid runs into the'space 58 between the piston and the cylinder. As it does this some of, the members of the mass 55 adjacent the lower surface of' the piston crowd towards the space 58 and tend to seal this space thus reducing the need for an accurate fit between the piston and cylinder. When pressure is removed from the resilient liquid mass the liquid in the space 58 is forced inwardly pressure.

In Fig. 14 the mass 59 is shown as confined in the cylindrical portion 50 of a clutch-like device iii in which the member 60 is driven by a shaft 52, with 53 the driven shaft having a pilot bearing 64 and splined at 55 to a clutch member 66 which is in the nature of a piston sliding in the cylinder 50. The member 65 may be moved by a suitable clutch yoken51 or in anyother desired manner. In operation as the driven member rotates, centrifugal force causes the mass to be set in circulation and pressure of the mass 59 to be increased'and as the mass becomes compacted a clutching effect occurs and when due to increased speed sufiicient pressure has been applied to the contained fluid mass, the clutching effectwill be completed. The fluid mass being compressible the clutch member 66 may be shifted to control the capacity of the clutch chamber to thereby control, in a degree, the clutching action.

Havingthus described the invention I claim:

1. In a fluid transmission, a fluid turbo device having a primary member normally driven by an input shaft and a secondary member subject to the torque of a load shaft, the device including a working circuit which includes a liquid having therein hollow, discrete, non-coalescing, inflated, elastic members of a size to be freely movable in and with the liquid.

2. In a fluid transmission, a having a primary member normally driven by an input shaft and a secondary member subject to the torque of a load shaft, the device including a working circuit which includes a liquid having therein hollow,- discrete, non-coalescing, in-

fiated, resilient members of a size to be freely by atmospheric air fluid turbo device- 

